I've extended my silk road travel to Japan. Even if Japan is not covered by Caravanistan, I think my (negative) consulate report might still be useful for others.

The Russian embassy in Japan requires at least a 90d permission in Japan. Tourists from certain countries are allowed to stay for 6M in Japan. My home country Switzerland is among these countries. I went to the Japanese immigration police and extended my stay. I've got a second "Temporary Vistor" stamp in my passport. The extension process in Tokyo was very smooth and done within two hours. In the waiting hall, they have even scissors and glue! I had to write down my future itinerary.

After 4 months traveling in Japan, I went to the Russian embassy in Osaka and applied for a "3M Double Entry Business Visa". They checked it, the clerk phoned with his boss and then they refused my visa application. They said the status "Temporary Visitor" in Japan, even if the stay permission is 6 months, is not enough. The Russian embassy requires "some sort of residency permission in Japan". Additionally, my visa application looked "too less business". They suggested applying at home for a tourist visa.

PS. I forgot to mention. They also said that the letter of invitation (LOI) must be the original and not a printout.

BTW: I've heard of a Swiss couple trying to get a Russian tourist visa in Seoul (South Korea). They were turned down as well.